JPH10211764A - Ink jet recording sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To little generate gloss like bronze on an image after storage without occurrence of ink set-off or ink stain in obtained image at a high humidity in the case of forming the image with high transparency by forming the image by ink jet recording. SOLUTION: This sheet comprises a support and a coloring material receiving layer provided on the support. In this case, the layer is formed of a mixture of at least one type of polymer of copolymer of polyvinyl alcohol, polyvinylpyrrolidone and vinylpyrrolidone and other monomer copolymerizable with the vinylpyrrolidone, and sole polymer of vinyl monomer having an imidazole group and at least one type of polymer of copolymer of the vinyl monomer having imidazole group and other monomer copolymerizable with the vinyl monomer, and the layer is a surface layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an ink jet recording sheet for forming an image sheet by ink jet recording.

[0002]

2. Description of the Related Art In recent years, with the rapid development of the information industry, various information processing systems have been developed, and recording methods and apparatuses suitable for each information system have been developed and adopted. In such a recording method, in an ink jet recording in which ink is ejected for recording, and in a thermal transfer recording using a fusion type coloring material or a sublimation type coloring material, an apparatus used is light and compact, and noise is reduced. No,
It has excellent operability and maintainability. further,
Ink-jet recording color printers have recently been widely used because devices used for ink-jet recording can be easily converted to color.

Various types of ink jet recording systems for forming color images have been developed, but the physical properties are roughly divided into a method using a color material solution (aqueous ink) containing a water-soluble dye or a fine particle pigment, and There are three methods: a method using a dye solution (oil-based ink) containing an oil-soluble dye, and a method using heat-melting a low-melting solid wax (wax ink) containing a dye. The mainstream is a type using an aqueous ink. In any case, this is a method of forming an image by ejecting liquid fine droplets onto an inkjet recording sheet.

[0004] The above-described image formation by ink jet recording is performed on ordinary paper, and in the following applications, it is necessary to use a transparent sheet. In many cases, a color material receiving (absorbing) layer is provided on the surface. The recording sheet having an image is prepared by forming an image as described above using the transparent film thus obtained. For example, an OHP film that is increasingly used in place of a slide in a meeting or the like, a backlight display film that is increasingly used in place of a printed poster or a display board, and a film for a second original drawing are cited. be able to. In addition, a hard copy in which an image is formed on an ink jet recording sheet may have a fine image and a higher gloss level than that formed on ordinary paper in some cases. That is, when considering silver halide photography which is ideal for hard copy, high glossiness is an important subject to be achieved.

Accordingly, in ink-jet recording,
It absorbs liquid ink quickly to obtain a fine image, has good ink transferability (the degree of ink density transferred to paper when paper is pressed against a printed ink image), and does not cause ink bleeding In order to form a color material receiving layer and further a transparent positive or high gloss image sheet as described above, a highly transparent color material receiving layer is required. A conventional colorant receiving layer mainly composed of a resin is excellent in transparency, but easily swells or dissolves with ink and becomes tacky, so it can be said that ink transferability (ink transferability) is very good. Absent.

[0006] In the case of ink jet recording, for example, Japanese Patent Application Laid-Open No. 56-80489 proposes the use of a soluble or swellable substance, and a large number of polymer systems (polyvinyl alcohol (PVA), polyvinyl pyrrolidone (PV)).
P), polyethylene oxide (PEO), carboxymethyl cellulose (CMC)). However, such a polymer colorant receiving layer is excellent in transparency but not satisfactory in ink absorption and ink transferability. That is, such a coloring material receiving layer utilizes the effect of penetration of the aqueous ink by the hydrophilic group or the dissociable group of the polymer, and the ink absorption is not sufficient even when the film is thickened. Of course, the ink transferability is not satisfactory. JP-A-3-104683 proposes to use crosslinked polyvinylpyrrolidone for the material of the colorant receiving layer. The use of such a colorant receiving layer improves ink transferability somewhat, but is not satisfactory. That is, if the crosslinking proceeds excessively, the ink absorbency decreases, and the ink transferability also deteriorates.

[0007] JP-A-63-307979 discloses that a gelatin, a hydrophilic polymer mordant and -C
A layer comprising a mixture of three types of polymers having vinyl monomer units having OOM or —SO ₃ M (corresponding to a colorant receiving layer), and further having a gelatin surface layer provided thereon for inkjet recording A seat has been proposed. Examples of hydrophilic polymer mordants include polymers having an amino group, an imidazole group or a cyano group. By using such a combination of specific polymers, an image formed by inkjet recording has improved resolution, and the occurrence of ink reflection,
Although the occurrence of ink bleeding under high humidity is suppressed, it is not sufficient.

[0008]

According to the study of the present inventor, polyvinyl alcohol (PVA) is preferable as the water-soluble resin which is the main material of the colorant receiving layer, since the occurrence of ink transfer is small. However, it has become clear that when an image is formed by ink jet on a colorant receiving layer mainly composed of PVA and stored, ink bleeding is likely to occur and the image may have a bronze gloss. . Further studies by the present inventors have revealed that, among the hydrophilic polymer mordants described in JP-A-63-307979, a polymer having an imidazole group is PVD.
When used with A, it was found that the ink bleeding was further improved and the generation of bronze gloss was suppressed to some extent. In order to suppress the occurrence of bronze luster without deteriorating other properties, it has been studied repeatedly, and it can be achieved by further adding polyvinylpyrrolidone to a system of a polymer having imidazole groups and PVA. It is clear that the present invention has been reached.

According to the present invention, an image can be formed by ink-jet recording, has high transparency, and when the image is formed, the obtained image is not affected by ink bleeding or ink bleeding under high humidity. It is an object of the present invention to provide an ink jet recording sheet in which no bronze-like gloss is observed in an image after storage, in which no gloss is observed. In addition, the present invention can form an image by inkjet recording, has high transparency or high gloss, and when an image is formed, occurrence of ink reflection and occurrence of ink bleeding under high humidity are also observed. It is another object of the present invention to provide an ink jet recording sheet which hardly shows bronze-like gloss in an image after storage.

[0010]

The present invention relates to a recording sheet comprising a support and a color material receiving layer provided thereon, wherein the color material receiving layer comprises polyvinyl alcohol, polyvinylpyrrolidone and vinylpyrrolidone. And at least one polymer selected from the group consisting of copolymers of other monomers copolymerizable with vinylpyrrolidone, and a homopolymer of a vinyl monomer having an imidazole group and a vinyl monomer having an imidazole group; and the vinyl monomer Consisting of a mixture of at least one polymer selected from the group consisting of copolymers with other copolymerizable monomers,
And the colorant receiving layer is a surface layer.

Preferred embodiments of the ink jet recording sheet of the present invention are as follows. 1) The colorant receiving layer contains polyvinyl alcohol in the range of 20 to 80% by weight of the whole polymer. 2) The colorant receiving layer is formed of at least one polymer selected from the group consisting of polyvinylpyrrolidone and a copolymer of vinylpyrrolidone and another monomer copolymerizable with vinylpyrrolidone (hereinafter also referred to as a vinylpyrrolidone-based polymer). , 5 to 50% by weight of the total polymer. 3) The colorant receiving layer is at least selected from the group consisting of a homopolymer of a vinyl monomer having an imidazole group and a copolymer of a vinyl monomer having an imidazole group and another monomer copolymerizable with the vinyl monomer. One type of polymer (hereinafter also referred to as an imidazole group-containing polymer) is contained in the range of 1 to 60% by weight of the whole polymer. 4) The colorant receiving layer is formed of polyvinyl alcohol, vinylpyrrolidone-based polymer and imidazole group-containing polymer,
The weight ratio is 20 to 80: 5 to 50: 1 to 60 (however, the sum of the three polymers is 100). 5) The water-soluble resin of the colorant receiving layer is crosslinked. 6) The support is a white polyester film. 7) The support is a transparent film made of polyester. 8) In the above item 6), the parallel light transmittance of the recording sheet is 83%.
(Especially 85% or more). 9) In the above item 7), the glossiness of the recording sheet is 75% or more (particularly, 80% or more). 10) The colorant receiving layer further contains 0.01 to 5% by weight of a matting agent. 11) The ink used for inkjet recording is an aqueous ink (50% by weight or more of the solvent is water). 12) An undercoat layer is provided between the support and the colorant receiving layer.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The ink jet recording sheet of the present invention has a basic structure comprising a support and a colorant receiving layer provided on one surface of the support. Color material receiving layers may be provided on both sides of the support.

The ink jet recording sheet of the present invention comprises:
For example, it can be manufactured as follows. In the present invention, any of a transparent support, a high gloss opaque support and a low gloss opaque support can be used as the support. As a material that can be used as the transparent support, a material that is transparent and has a property of withstanding radiant heat when used in an OHP or a backlight display is preferable. Examples of such a material include polyesters such as polyethylene terephthalate; cellulose esters such as nitrocellulose, cellulose acetate, and cellulose acetate butyrate; and polysulfone, polyphenylene oxide, polyimide, polycarbonate, and polyamide. Among these, polyesters are preferred, and polyethylene phthalate is particularly preferred. As the high gloss opaque support, those having a glossiness of 20% or more on the surface on which the color material receiving layer is provided are preferable. The glossiness is a 45-degree specular glossiness of each support.

Examples of high-gloss opaque supports include high-gloss paper such as art paper, coated paper, cast-coated paper, and baryta paper used for silver halide photographic supports; polyethylene terephthalate (PET), etc. Polyesters, nitrocellulose, cellulose esters such as cellulose acetate and cellulose acetate butyrate, further polysulfone, polyphenylene oxide, polyimide,
High gloss film (which may be subjected to surface calendering or the like) made of a plastic film such as polycarbonate or polyamide by adding a white pigment or the like to the film, or the above-mentioned various papers, the above-mentioned transparent plastic film or white pigment Films in which a polyolefin coating layer containing or not containing a white pigment is provided on the surface of a plastic containing the same. Further, a foamed polyester film containing a white pigment (eg, a calcium-containing foamed PET containing fine polyolefin particles to form voids by stretching, and a film containing barium sulfate to form voids by stretching) can also be mentioned. Also, polyolefin-coated paper used as a silver salt photographic support (a type of support provided with a polyolefin coating layer such as a paper support having a white pigment-containing polyolefin layer on its surface), or a metal deposition layer Special paper or the like provided with the like can be suitably used. In the present invention, a white plastic film (particularly, a polyester film) containing the above white pigment is preferable. In particular, a paper support provided with a white pigment-containing polyolefin layer, a polyester (preferably PET) film provided with a white pigment-containing polyolefin layer, a white pigment-containing polyester film, or a white pigment-containing foamed polyester film is preferable. As an example of the opaque support having low gloss, general paper can be mentioned. The thickness of the support is not particularly limited.
Those having a thickness of 0 μm are preferred because they are easy to handle.

It is preferable to provide an undercoat layer on the support. The undercoat layer is a layer made of a polymer. Examples of the polymer include a styrene-butadiene copolymer, a vinylidene chloride polymer, a vinyl chloride polymer, a vinyl acetate polymer, polyvinyl formal, polyvinyl butyral,
Examples thereof include a vinylidene fluoride polymer, a vinylidene fluoride polymer, a polyester resin, a polyamide resin, and an acrylic resin. Styrene-butadiene copolymer,
Preferred are vinylidene chloride-based polymers, vinylidene fluoride-based polymers, vinylidene fluoride-based polymers, polyester resins, polyamide resins, and acrylic resins, and particularly preferred are styrene-butadiene-based copolymers and vinylidene chloride-based polymers. The polymer preferably has a hydroxyl group, a carboxyl group, an amino group, and a carbonyldioxy group by introducing a copolymer component. Further, the undercoat layer is preferably formed from a latex of the above polymer. In particular, it is preferably formed from a styrene-butadiene-based latex or a vinylidene chloride-based latex. Styrene-butadiene-based latex and vinylidene chloride-based latex are, as other copolymerization components, hydroxyl-containing (meth) acrylic monomers (eg, hydroxyethyl acrylate) and (meth) acrylate monomers (eg, methyl acrylate, methyl methacrylate) ),
It generally contains acrylonitrile, a (meth) acrylic monomer having a carboxyl group (eg, acrylic acid), a polyfunctional monomer (eg, divinylbenzene) in an amount of 20 mol% or less.

The undercoat layer preferably contains a crosslinking agent (which also functions as an adhesion-imparting agent). Examples of the crosslinking agent include aldehydes (eg, formaldehyde, glyoxal and glutaraldehyde), N-methylol compounds (eg, dimethylol urea and methylol dimethylhydantoin), dioxane derivatives (eg, 2,
3-dihydroxydioxane), a compound that acts by activating a carboxyl group (eg, carbenium,
2-naphthalenesulfonate, 1,1-bispyrrolidino-1-chloropyridinium and 1-morpholinocarbonyl-3- (sulfonatoaminomethyl)), active vinyl compounds (eg, 1,3,5-triacloyl-hexahydro-s-) Triazine, bis (vinylsulfone) methane and N, N'-methylenebis- [β- (vinylsulfonyl)
Propionamide]), triazine derivatives (eg, 2,4
-Dichloro-6-hydroxy-S-triazine), a compound having an epoxy group (eg, bisphenol A type epoxy resin, glycidyl versatate, phenyl glycidyl ether), isoxazoles, melamine resin, isocyanate compound and dialdehyde starch ,
And the like. These can be used alone or in combination. Of these, triazine derivatives are preferred. The amount of the crosslinking agent to be added is preferably 0.1 to 20% by weight, and more preferably 0.5 to 15% by weight.
% By weight is preferred.

The polymer mainly constituting the undercoat layer may be a single material or a mixture of a plurality of materials. For the undercoat layer, in addition to the above-mentioned polymer, the above-mentioned crosslinking agent and various surfactants may be used for the purpose of improving coating suitability and surface quality. The formation of the undercoat layer can be carried out, for example, by applying the above polymer latex and, if desired, an aqueous dispersion (coating solution) containing a crosslinking agent on a support and drying by heating. The coating can be performed by a known coating method such as an air doctor coater, a bread coater, a rod coater, a knife coater, a squeeze coater, a reverse roll coater, a wire bar coater, and a bar coater. Drying is usually performed at 50 to 180 ° C. with a hot air drier at 1 to 20 ° C.
Although drying is performed for 90 minutes, it is preferable to dry at 90 to 150 ° C. for 2 to 15 minutes. The layer thickness of the undercoat layer thus formed is generally in the range of 0.05 to 10 μm, and 0.1 to 10 μm.
A range of 5 μm is preferred. The surface of the support on which the undercoat layer is formed is subjected to a surface treatment such as a corona discharge treatment, a plasma treatment, a flame treatment, and an ultraviolet irradiation treatment in order to further improve the adhesion between the support and the undercoat layer. It is preferred to do so.

The colorant receiving layer of the present invention is formed on the support or the undercoat layer. The colorant receiving layer of the present invention is a surface layer, and no layer is provided on this layer. The colorant receiving layer is formed of at least one polymer selected from the group consisting of polyvinyl alcohol, polyvinylpyrrolidone, a copolymer of vinylpyrrolidone and another monomer copolymerizable with vinylpyrrolidone (vinylpyrrolidone-based polymer), and an imidazole group. Of at least one polymer (imidazole group-containing polymer) selected from the group consisting of a homopolymer of a vinyl monomer having a vinyl monomer and a copolymer of a vinyl monomer having an imidazole group and another monomer copolymerizable with the vinyl monomer Consists of For example, a water-soluble resin solution obtained by dissolving this mixture (or each polymer) in water (using a hydrophilic solvent as appropriate) is used to coat the surface of the undercoat layer provided on the support or the support. By applying and drying, a colorant receiving layer can be formed.

Examples of the polyvinyl alcohol include unmodified polyvinyl alcohol and modified polyvinyl alcohol such as ethylene-modified polyvinyl alcohol, cation-modified polyvinyl alcohol, anion-modified polyvinyl alcohol, and silanol-modified polyvinyl alcohol. Unmodified polyvinyl alcohol is preferred. The saponification degree is generally in the range of 60 to 99.9, preferably 70 to 99. The degree of polymerization is 100 to 300
The range of 0 is common, and 500-3000 is preferable.

Further, as the material of the colorant receiving layer, a vinylpyrrolidone-based polymer (ie, at least one of polyvinylpyrrolidone and a copolymer of vinylpyrrolidone and another monomer copolymerizable with vinylpyrrolidone) is used. Other monomers copolymerizable with vinylpyrrolidone include vinyl acetate, styrene, various acrylic monomers (eg, methyl methacrylate), maleic anhydride, vinyl chloride, ethylene, and the like. Vinyl acetate is preferred. Such vinylpyrrolidone-based polymers include polyvinylpyrrolidone or vinylpyrrolidone /
Vinyl acetate copolymers are preferred. Particularly, polyvinylpyrrolidone is preferred. The ratio of vinylpyrrolidone to other monomers is preferably in the range of 99/1 to 50/50 (molar ratio).

Further, as a material of the colorant receiving layer, an imidazole group-containing polymer (ie, a homopolymer of a vinyl monomer having an imidazole group, a vinyl monomer having an imidazole group, and another monomer copolymerizable with the vinyl monomer) may be used. At least one polymer selected from the group consisting of the above copolymers). Examples of such a vinyl polymer include a vinyl monomer having an imidazole group (eg, vinyl imidazole, 1-vinyl-3-methylimidazole salt, imidazolinomethylene styrene,
Homopolymer of vinyl-3-hydroxyethylimidazole salt, 1-vinyl-2-methylimidazole); and a vinyl monomer having an imidazole group and at least one other monomer copolymerizable with the vinyl monomer (eg, vinylpyrrolidone) , P-styrene sulfonate,
p-styrene sulfinate, acrylonitrile, styrene, methyl methacrylate). As the vinyl monomer having an imidazole group, a vinyl monomer having an unsubstituted imidazole group is preferable, and vinylimidazole is particularly preferable. As other copolymerizable monomers, vinylpyrrolidone, p-styrenesulfonate, and p-styrenesulfinate are preferred. The polymer preferably has at least 30 mol%, and preferably at least 40 mol%, of a vinyl monomer unit having an imidazole group.

Preferred examples of the imidazole group-containing polymer are shown below.

[0023]

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[0024]

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[0025]

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[0026]

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Of the above, the polymers a) to f) are particularly preferred.

The colorant receiving layer of the present invention preferably contains the polyvinyl alcohol in the range of 20 to 80% by weight of the total polymer, and particularly preferably 30 to 70% by weight. Further, the vinylpyrrolidone-based polymer is used in an amount of 5 to 5
It is preferably contained in the range of 0% by weight, particularly preferably 5 to 30% by weight. Further, the imidazole group-containing polymer is preferably contained in the range of 1 to 60% by weight of the whole polymer, and particularly preferably 2 to 50% by weight. The colorant receiving layer comprises a polyvinyl alcohol, a vinylpyrrolidone-based polymer and an imidazole group-containing polymer in a weight ratio of 20.
８０80: 5５０50: 1１〜60 (however, the sum of the three polymers is 100), preferably 30 含 む 70: 5３０30: 2５０50. . As described above, the PVA is used as the water-soluble resin.
By using a vinylpyrrolidone-based polymer together with the above imidazole group-containing polymer, it is possible to obtain a colorant receiving layer which is excellent in ink bleeding and ink transferability and hardly generates bronze luster. In addition, the vinylpyrrolidone-based polymer contributes to improvement in applicability (leveling) when forming the colorant receiving layer by coating.

In addition to the above three polymers, other water-soluble resins may be used. Examples of such a water-soluble resin include, as a resin having a hydroxyl group as a hydrophilic structural unit, a cellulose resin (methylcellulose (M
C), ethyl cellulose (EC), hydroxyethyl cellulose (HEC), carboxymethyl cellulose (C
MC) etc.), chitins and starch; polyethylene oxide (PEO) as a resin having an ether bond,
Polypropylene oxide (PPO), polyethylene glycol (PEG) and polyvinyl ether (PVE)
And polyacrylamide (PAAM) as a resin having an amide group or an amide bond. Further, a polyacrylate having a carboxyl group as a dissociable group, a maleic acid resin, an alginate and gelatins; a polystyrene sulfonate having a sulfone group, an amino group, an imino group, a tertiary amine and a quaternary ammonium salt. Having polyallylamine (PAA), polyethyleneimine (PEI), epoxidized polyamide (EPA
m), polyvinyl pyridine and gelatins.

The above water-soluble resin is preferably crosslinked with a crosslinking agent in order to improve the water resistance of the colorant receiving layer. That is, it is preferable to form a colorant receiving layer by adding a crosslinking agent to a coating solution containing a polymer particle crosslinked with a water-soluble resin, applying the crosslinking agent to a support, and drying by heating (crosslinking). . Examples of the crosslinking agent include aldehydes (eg, formaldehyde, glyoxal and glutaraldehyde), N-methylol compounds (eg, dimethylol urea and methylol dimethylhydantoin), dioxane derivatives (eg, 2,3-dihydroxydioxane), carboxyl Compounds that act by activating groups (eg, carbenium, 2-naphthalenesulfonate, 1,1-bispyrrolidino-1-chloropyridinium and 1-morpholinocarbonyl-3- (sulfonatoaminomethyl)), active vinyl compounds (E.g.,
1,3,5-triacroyl-hexahydro-s-triazine, bis (vinylsulfone) methane and N, N'-
Methylene bis- [β- (vinylsulfonyl) propionamide]), an active halogen compound (eg, 2,4-dichloro-6-hydroxy-S-triazine), a compound having an epoxy group (eg, bisphenol A type epoxy resin,
Versatic acid glycidyl ester, phenyl glycidyl ether), isoxazoles, melamine resin,
Examples include isocyanate compounds and dialdehyde starch. These can be used alone or in combination. In consideration of productivity, it is preferable to use an aldehyde such as glutaraldehyde having a high reaction activity or a melamine resin. The crosslinking agent is particularly effective for polyvinyl alcohol. The amount of the crosslinking agent added
0.1 to 20% by weight based on the water-soluble resin is preferable,
Particularly, 0.5 to 15% by weight is preferable.

In the colorant receiving layer of the present invention, in addition to the above three resins, a matting agent such as silica, colloidal silica, calcium silicate, zeolite is used as a matting agent for improving the running properties and blocking resistance of the ink jet recording sheet. ,
Inorganic fine particles such as kaolinite, halloysite, muscovite, talc, calcium carbonate, calcium sulfate and boehmite, or organic fine particles such as polymethyl methacrylate fine particles, polystyrene fine particles and polyethylene fine particles may be contained. As the inorganic fine particles, silica and colloidal silica are preferable, and as the organic fine particles, polymethyl methacrylate fine particles are preferable. The content of the matting agent in the colorant receiving layer is preferably in the range of 0.01 to 5% by weight.

Each of the above resins mainly constituting the color material receiving layer may be a single material or a mixture of a plurality of materials. The colorant receiving layer is mainly composed of the above, but in addition to the above, various inorganic salts, PH, etc.
An acid or an alkali may be contained as a regulator. In addition, various surfactants may be used for the purpose of improving coating suitability and surface quality. Further, a mordant may be used for the purpose of fixing dyes and increasing water resistance in ink jet recording. Further, various matting agents may be included for the purpose of reducing the friction characteristics of the surface. Further, various antioxidants and ultraviolet absorbers may be contained for the purpose of suppressing the deterioration of the coloring material. Further, a fluorescent whitening agent may be included.

The formation of the color material receiving layer can be carried out, for example, by applying an aqueous solution (coating solution) containing the above resin or the like on a transparent support and drying by heating. Application is
For example, the coating can be performed by a known coating method such as an air doctor coater, a bread coater, a rod coater, a knife coater, a squeeze coater, a reverse roll coater, and a bar coater. The aqueous solution may use a hydrophilic solvent (eg, methanol, ethanol, isopropyl alcohol, n-butanol) in addition to water as a solvent. Drying is usually performed at 50 to 180 ° C with a hot air drier for 1 hour.
Drying is carried out for 20 to 20 minutes, preferably at 90 to 150 ° C. for 2 to 15 minutes. Further, after coating and drying, for example, by passing through a roll nip under heating and pressure with a super calender, gloss calender or the like, it is possible to improve the surface smoothness, transparency and coating film strength.

In the coloring material receiving layer thus obtained,
When an image is formed, the resulting image does not show any ink transfer or ink bleeding under high humidity, and almost no bronze-like gloss appears in the image after storage. Among the resins constituting the color material receiving layer, polyvinyl alcohol (PVA) has a function of absorbing the ink, and the imidazole group-containing polymer has particularly good affinity with the ink and improves the ink bleeding property, etc. It also has a function of suppressing the occurrence of gloss. Further, the vinylpyrrolidone-based polymer particularly suppresses the occurrence of bronze-like gloss and improves coatability, so that a smooth coated surface can be obtained, so that an ink jet recording sheet having the above-described excellent properties can be obtained. . Since the imidazole group-containing polymer and the vinylpyrrolidone-based polymer can prevent crystallization of the dye in the ink forming the image on the colorant receiving layer, even if the obtained image is stored for a long time, It is considered that there is no occurrence of bronze-like gloss in the image, which is effective in providing an image with excellent image quality for a long period of time. Further, the coating liquid of PVA and the imidazole group-containing polymer cannot be said to have good coatability, and a good coatability is obtained by using a vinylpyrrolidone-based polymer in combination, and a smooth coated surface is obtained. Thus, the colorant receiving layer formed from the above three kinds of resins has the above excellent characteristics.

Further, since the coloring material receiving layer of the present invention does not require the use of inorganic fine particles which are usually used for improving ink transferability, the coloring material receiving layer has high transparency and is suitable for preparing OHP sheets. Can be used. Alternatively, even when the highly transparent colorant receiving layer of the present invention is provided on a support having high gloss, a high quality ink image can be formed without impairing the high gloss of the support. . In the ink jet recording sheet having the color material receiving layer provided on the transparent support, the sheet itself generally has a transmittance of 80% or more because the color material receiving layer has a high transmittance. 83%
Or more, and particularly preferably 85% or more. In addition, the ink jet recording sheet in which the color material receiving layer is provided on a high gloss opaque support generally has a sheet surface gloss of 70% or more, preferably 75% or more, and particularly preferably 80% or more.
% Or more is preferable.

[0036]

【Example】

Example 1 Composition of Coating Solution for Forming Coloring Material Receiving Layer Polyvinyl alcohol 20% by weight aqueous solution 31.9 parts by weight (Saponification degree: 81; PVA405, manufactured by Kuraray Co., Ltd.) Polyvinylpyrrolidone 10% by weight aqueous solution 22 0.8 parts by weight (PVPK-90, manufactured by ISP) 10 parts by weight aqueous solution of imidazole group-containing polymer 4.6 parts by weight (polymer of (d) of the above polymer example) Matting agent 0.7 parts by weight (MX-1000 (PMMA Particles: 4% by weight aqueous dispersion, manufactured by Soken Chemical Co., Ltd.) Melamine resin 4.1 parts by weight (10% by weight aqueous dispersion of Sumireze # 613, manufactured by Sumitomo Chemical Co., Ltd.) Amine hydrochloride 0.8% by weight Part (5% by weight aqueous dispersion of ACX-P, manufactured by Sumitomo Chemical Co., Ltd.) Surfactant 1.8 parts by weight (10% by weight aqueous solution of F-144D, Dainippon Ink and Chemicals, Inc.) To obtain a colorant-receiving layer coating solution by mixing the materials Ltd.)) Water 33.3 parts by weight The above composition.

This coating solution was applied to the surface of a white polyethylene terephthalate film (D534, manufactured by ICI Japan) using a bar coater, and dried at 120 ° C. for 10 minutes using a hot air drier. As a result, a color material receiving layer having a dry film thickness of 10 μm was formed. Thus, an ink jet recording sheet having a color material receiving layer provided on a white polyethylene terephthalate film was obtained.

Example 2 Example 1 was the same as Example 1 except that the imidazole group-containing polymer of the coating material for forming a colorant receiving layer was changed from the polymer (d) to the polymer (e) in the polymer examples. In the same manner as in the above, an ink jet recording sheet was prepared.

Example 3 The procedure of Example 1 was repeated, except that the imidazole group-containing polymer of the coating material for forming a colorant receiving layer was changed from the polymer (d) to the polymer (b). In the same manner as in the above, an ink jet recording sheet was prepared.

Example 4 An ink jet recording sheet was prepared in the same manner as in Example 1 except that the white polyester film was changed to a polyethylene terephthalate film (100 μm thick) whose surface was subjected to corona discharge treatment. Created.

Example 5 In Example 1, the aqueous solution of 20% by weight polyvinyl alcohol in the coating material for forming a colorant receiving layer was changed from 31.9 parts by weight to 25.5 parts by weight.
The 10% by weight aqueous solution of polyvinylpyrrolidone was changed from 22.8 parts by weight to 4.6 parts by weight, and the 10% by weight aqueous solution of a polymer containing imidazole groups was changed from 4.6 parts by weight to 32.2 parts by weight.
An ink jet recording sheet was prepared in the same manner as in Example 1 except that the weight was changed.

Example 6 In Example 1, the 20% by weight aqueous solution of polyvinyl alcohol in the coating material for forming a colorant receiving layer was changed from 31.9 parts by weight to 21.3 parts by weight.
The 10% by weight aqueous solution of polyvinylpyrrolidone was changed from 22.8 parts by weight to 4.6 parts by weight, and the 10% by weight aqueous solution of a polymer containing imidazole groups was changed from 4.6 parts by weight to 41.4 parts by weight.
An ink jet recording sheet was prepared in the same manner as in Example 1 except that the weight was changed.

Example 7 In Example 1, the aqueous solution of 20% by weight polyvinyl alcohol in the coating material for forming a colorant receiving layer was changed from 31.9 parts by weight to 21.3 parts by weight.
Then, a 10% by weight aqueous solution of polyvinylpyrrolidone was added to 22.
An ink jet recording sheet was prepared in the same manner as in Example 1 except that the amount was changed from 8 parts by weight to 41.0 parts by weight.

Comparative Example 1 Composition of Coating Solution for Forming Coloring Material Receptive Layer Gelatin 10% by weight aqueous solution 20 parts by weight 10% by weight solution of polymer (A) having COONa 10 parts by weight (the following polymer (A)) imidazole 40% by weight of a 10% by weight aqueous solution of a group-containing polymer (polymer of (b) in the above polymer example) 30% by weight of water

[0046]

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The materials having the above composition were mixed to obtain a coating material for forming a colorant receiving layer. The coating solution was applied to the surface of a white polypolyethylene terephthalate film (D534, manufactured by ICI Japan) using a bar coater, and dried at 120 ° C. for 10 minutes using a hot air drier. As a result, a color material receiving layer having a dry film thickness of 10 μm was formed. A gelatin solution was applied on the colorant receiving layer to form a gelatin layer having a thickness of 0.5 μm. Thus, an ink jet recording sheet having a color material receiving layer and a gelatin layer provided on a white polyethylene terephthalate film was obtained.

Comparative Example 2 Composition of Coating Solution for Forming Coloring Material Receptive Layer 10% by weight aqueous solution of gelatin 30 parts by weight 10% by weight aqueous solution of imidazole group-containing polymer 45 parts by weight (Polymer (d) in the above polymer example) Water 25 Parts by weight

The materials having the above composition were mixed to obtain a coating material for forming a colorant receiving layer. The coating solution was applied to the surface of a white polypolyethylene terephthalate film (D534, manufactured by ICI Japan) using a bar coater, and dried at 120 ° C. for 10 minutes using a hot air drier. As a result, a color material receiving layer having a dry film thickness of 10 μm was formed.

Composition of Coating Solution for Forming Surface Layer: 10% by weight of 10% by weight solution of polymer (A) having COONa (the above polymer (A)) 10% by weight of 10% by weight aqueous solution of hardener (B) 30% by weight of water Department

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The materials having the above composition were mixed to obtain a coating solution for forming a surface layer. This coating solution was applied on the color material receiving layer to form a surface layer having a thickness of 1.0 μm. Thus, an ink jet recording sheet having a color material receiving layer and a surface layer provided on a white polyethylene terephthalate film was obtained.

With respect to the ink jet recording sheet provided with the undercoat layer and the colorant receiving layer on the transparent support obtained above, the ink jet suitability was evaluated by the following measuring method. (1) Ink transferability Solid printing of yellow (Y), magenta (M), cyan (C), and black (K) was performed on a recording sheet using an inkjet color printer (PM-700C; manufactured by Seiko Epson Corporation). 20 minutes later, copy paper (PPC (electrophotographic copying machine) paper WR, manufactured by Fuji Xerox Co., Ltd.) is contact-pressed with a rubber roller (condition: linear pressure of 0.6 kg / cm).
did. Then, the amount of ink transferred to the copy paper was visually evaluated. AA: No transfer in the print area was observed. BB: Slight transfer of the print area is observed. CC: The print portion was transferred, and traces indicating that the image had disappeared due to the transfer were also seen in the color material receiving layer. (2) Bronze gloss Using the same printer as in (1) above, black solid printing was performed on the recording sheet, and the printed sheet was heated at 23 ° C and 65 ° C.
% RH for 24 hours, and the black print after the standing was visually evaluated as follows. AA: No bronze-like gloss was observed. BB: Bronze-like luster is partially observed. CC: Bronze-like luster is observed on the entire surface. (3) Blurring of image under high humidity Using the same printer as in (1), solid printing of yellow (Y), magenta (M), cyan (C), and black (K) is performed on the recording sheet. And the printed recording sheet at 28 ° C. and 85
It was left for 3 days in an environment of% RH. The degree of bleeding of the solid print area was visually evaluated as follows. AA: No bleeding is seen in the solid printing part. BB: Bleeding is seen in a part of the solid printing part. CC: Bleeding is seen in a considerable part of the solid printing part. (4) Glossiness It is obtained in the above Examples and Comparative Examples. The glossiness of the high gloss opaque support and the recording sheet was measured at an incident angle of 45 degrees as follows. That is, six test pieces were prepared and measured using a gloss meter (digital variable-angle gloss meter, manufactured by Suga Test Instruments Co., Ltd.). The average value of the obtained measured values was defined as the glossiness. (5) Parallel light transmittance haze meter (HGM-2DP; Suga Test Instruments Co., Ltd.)
Was used to measure the parallel light transmittance.

The results of the above evaluation are shown in Table 1 below.

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[Table 1] Table 1 ──────────────────────────────────── Color material receiving layer Bronze ink Gloss (%) High humidity (composition / ratio) Gloss Reflectivity Support sheet Bleed ──────────────────────────────── ──── Example 1 PVA / PVP / (d) AA AA 52.6 90.7 AA = 63.8 / 22.8 / 4.6 Example 2 PVA / PVP / (e) AA AA 52.6 90.7 AA = 63.8 / 22.8 / 4.6 Example 3 PVA / PVP / (b) AA AA 52.6 91.4 AA = 63.8 / 22.8 / 4.6 Example 4 PVA / PVP / (d) AA AA-89.1 AA = 63.8 / 22.8 / 4.6 (transmittance) ─────── ───────────────────────────── Example 5 PVA / PVP / (d) AA AA 52.6 91.3 AA = 51.0 / 4.6 / 32.2 Example 6 PVA / PVP / (d) AA AA 52.6 91.6 AA = 42.6 / 4.6 / 41.4 Example 7 PVA / PVP / (d) AA BB 52.6 91.4 BB = 42.6 / 41.0 / 4.6 ──────── ────────────────────── ───── Comparative Example 1 gel / (A) / (b) BB CC 52.6 87.5 BB = 20/10/40 and gel Comparative Example 2 gel / (d) = 30/45 and BB CC 52.6 87.0 BB (A ) / (B) = 10/10 ──────────────────────────────────── Remarks) PVA: Polyvinyl Alcohol PVP: polyvinylpyrrolidone gel: gelatin (d) (e) (b) (f): imidazole group-containing polymer (A): polymer having -COONa (B): hardener

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According to the ink jet recording sheet of the present invention, when an image is formed, the obtained image does not show any ink reflection or ink bleeding under high humidity, and the image after storage. There is almost no occurrence of bronze-like luster. Among the resins constituting the colorant receiving layer of the recording sheet of the present invention, polyvinyl alcohol (PVA) has a function of absorbing ink, and an imidazole group-containing polymer has particularly good affinity for ink and ink bleeding property. Etc., and has a function of suppressing the occurrence of bronze-like luster to some extent. Further, the vinylpyrrolidone-based polymer particularly suppresses the generation of bronze-like gloss and improves the coatability, so that an ink jet recording sheet having the above-described excellent properties can be obtained. Further, since the coloring material receiving layer of the present invention is also excellent in transparency, the ink jet recording sheet of the present invention can be suitably used for preparing an image sheet requiring transparency such as an OHP sheet. . When the highly transparent coloring material receiving layer of the present invention is provided on a support having a high gloss, a high quality ink image can be formed without impairing the high gloss of the support.

Claims (6)

[Claims] 1. A recording sheet comprising a support and a coloring material receiving layer provided thereon, wherein the coloring material receiving layer is capable of copolymerizing with polyvinyl alcohol, polyvinylpyrrolidone, and vinylpyrrolidone and vinylpyrrolidone. At least one polymer selected from the group consisting of copolymers with other monomers, and a homopolymer of a vinyl monomer having an imidazole group and a vinyl monomer having an imidazole group and another monomer copolymerizable with the vinyl monomer; An ink jet recording sheet comprising a mixture of at least one polymer selected from the group consisting of the above-mentioned copolymers, and wherein the colorant receiving layer is a surface layer. 2. The colorant receiving layer according to claim 1, wherein said colorant receiving layer contains polyvinyl alcohol in the range of 20 to 80% by weight of the whole polymer.
3. The sheet for inkjet recording according to item 1. 3. The colorant receiving layer comprises at least one polymer selected from the group consisting of polyvinylpyrrolidone and a copolymer of vinylpyrrolidone and another monomer copolymerizable with vinylpyrrolidone; 2. The ink jet recording sheet according to claim 1, wherein said sheet is contained in a range of 50% by weight. 4. The colorant receiving layer comprises at least one polymer selected from the group consisting of a copolymer of a vinyl monomer having an imidazole group and another monomer copolymerizable with the vinyl monomer. The ink jet recording sheet according to claim 1, wherein the content of the sheet is in the range of about 60% by weight. 5. The ink jet recording sheet according to claim 1, wherein the support is a white polyester film. 6. The ink jet recording sheet according to claim 1, wherein the support is a transparent film made of polyester.